Door latch



J. PRENTICE Sept. 29, 1931.

noon LATCH Filed May 4, 192a lNVENTOR M ATTORNEYJ Patented Sept. 29, 1931 UNITEDSTATES PATENT OFFICE JOHN PRENTICE, OI BAYONNE, NEW JERSEY, ASSIGNOR TO THE B ABCOCK & WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY DOOR LATCH Application filed May 4, 1928. Serial No. 274,995.

This invention relates to a fastening device for a door that operates in such a manner that the danger of the door becoming accidentally opened is minimized or entirely avoided. The invention is especially applicable to furnace doors where there is danger of the doors being blown open by explosion in the furnace but is not restricted to this particular use. The invention will be understood from the description in connection with the accompanying drawin which Fig. 1 is a front view of the device, and Fig. 2 is an end view of the same viewed along the line 2-2 of Fig. 1. In the drawings reference character 1 indicates a wall upon which the door is mounted. The wall is provided with a flanged opening 2 with the front edge or face sloping as most clearly shown in Fig. 2.

The door 3 is provided with hinges 4 and is mounted upon a hinge pin 5 that is installed at a slight angle to the vertical so that the door will tend to close by gravity when it is opened less than 90. A latch 6 is pivoted to the door at one end as shown at 7 and a handle 8 for the latch is provided near the other end.

A catch 9 is attached to the wall 1 by means of the bolts 10 and is provided with a notch 11 into which the latch 6 is caught when the door is closed. A latch guide 12 is attached to the door 3 by means of the bolts 13 and carries a cylinder 14. The cylinder 14' has its upper end closed and its lower end open. It serves as a guide for a weight or plunger 15 that is located above the latch 6 so as to come into contact with the upper edge thereof. The weight or plunger 15 is shorter than the distance from the upper edge of the latch to the closed end of the cylinder 14. It is not necessary to have the'guide for the plunger 15 attached to the guide 12 as it may be attached to the door itself. It is sufficient to perform its function if it merely permits the weight to ride loosely upon the latch 6 and return to normal position at the proper time.

It has heretofore been found in devices of this character that the latchsometimes.

fails to become seated sufliciently in the notch which holds the door closed with the result that the door can be forced open by pressure from the inside. Merely increasing the weight of the latch does not overcome the difiiculty. By the present invention the loose plunger or weight 15 is provided to cause the latch to seat completely in the notch due to the fact that when the door is slammed and the latch 6 rides upon the sloping surface 16 of the catch 9, it is moved upwards suddenly, thus throwing the weight 15 upwardly into the cylinder 14 so that when the latch 6 reaches the posi- 2. A door having a latch pivoted at one end with its other end free to move in a vertically disposed plane, a guide on said door, a weight movable in a vertically disposed plane guided by said guide and adapted to contact with said latch, and a stop to limit the upward movement of said weight, said stop being positioned so that said weight can move upwardly after said latch has reached its uppermost position.

JOHN PRENTIOE. 

